<template>
  <div>
    <div class="goods">
        <div class="menu-wrapper" ref="menuWrapper">
          <ul>
            <li class="menu-item" v-for="(item, index) in goods" :key="index" :class="{'current': currentIndex === index}" @click="selectMenu(index)">
              <span class="text border-1px">
                <span class="icon" v-show="item.type > 0" :class="classMap[item.type]"></span>
                <span>{{item.name}}</span>
              </span>
            </li>
          </ul>
        </div>
        <div class="food-wrapper" ref="foodsWrapper">
          <ul>
            <li v-for="(item, index) in goods" :key="index" class="food-list food-list-hook">
              <h1 class="title">{{item.name}}</h1>
              <ul>
                <li v-for="(food, index) in item.foods" :key="index" class="food-item border-1px" @click="selectFood(food)">
                  <div class="icon">
                    <img :src="food.icon" width="57" height="57">
                  </div>
                  <div class="content">
                    <h2 class="name">{{food.name}}</h2>
                    <p class="desc">{{food.description}}</p>
                    <div class="extra">
                      <span class="count">月售{{food.sellCount}}份</span>
                      <span>好评率{{food.rating}}%</span>
                    </div>
                    <div class="price">
                      <span class="now">￥{{food.price}}</span>
                      <span class="old" v-show="food.oldPrice">{{food.oldPrice}}</span>
                    </div>
                    <div class="cartcontrol-wrapper">
                      <cartcontrol :food="food" @add="addFood"></cartcontrol>
                   </div>
                  </div>
                </li>
              </ul>
            </li>
          </ul>
        </div>
      </div>
      <shop-cart ref="shopcart" :delivery-price="seller.deliveryPrice" :min-price="seller.minPrice" :select-foods="selectFoods"></shop-cart>
      <food :food="selectedFood" ref="food" @cart-add="cartAdd"></food>
  </div>
</template>
<script>
import Bscroll from 'better-scroll'
import ShopCart from 'components/shopcart/shopcart'
import Cartcontrol from 'components/cartcontrol/cartcontrol'
import Food from 'components/food/food'
const ERR_OK = 0
export default {
  props: {
    seller: {
      type: Object
    }
  },
  data () {
    return {
      goods: [],
      scrollY: 0,
      listHeight: [],
      isRefresh: false,
      selectedFood: {}
      // isRefresh防止currentIndex变化的时候多次触发scrollTo方法，只有滚动到最后了我们再滚动的时候 currentIndex变化我们在让他滚动到最上面
    }
  },
  created () {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee']
    this.$http.get('/api/goods').then((res) => {
      if (res.data.errno === ERR_OK) {
        this.goods = res.data.data
        this.$nextTick(() => {
          console.log(this.goods)
          this._initScroll()
          this._caculateHeight()
        })
      }
    })
  },
  computed: {
    currentIndex () {
      for (var i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i]
        let height2 = this.listHeight[i + 1]
        if (!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          return i
        }
      }
      return 0
    },
    selectFoods () {
      let foods = []
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if (food.count) {
            foods.push(food)
          }
        })
      })
      return foods
    }
  },
  watch: {
    currentIndex (index) {
      if (index === this.goods.length - 1) {
        let menuItem = this.$refs.menuWrapper.getElementsByClassName('menu-item')
        let el = menuItem[index]
        this.menuScroll.scrollToElement(el, 300)
        this.isRefresh = true
      } else {
        if (this.isRefresh) {
          this.menuScroll.scrollTo(0, 0, 300)
          this.isRefresh = false
        }
      }
    }
  },
  methods: {
    cartAdd (target) {
      this.$refs.shopcart.drop(target)
    },
    selectFood (food) {
      this.selectedFood = food
      this.$refs.food.show()
    },
    selectMenu (index) {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
      let el = foodList[index]
      this.foodScroll.scrollToElement(el, 300)
    },
    addFood (etarget) {
      this._drop(etarget)
    },
    _drop (etarget) {
      // 体验优化 执行落下动画
      this.$nextTick(() => {
        this.$refs.shopcart.drop(etarget)
      })
    },
    _initScroll () {
      this.menuScroll = new Bscroll(this.$refs.menuWrapper, {
        click: true
      })
      this.foodScroll = new Bscroll(this.$refs.foodsWrapper, {
        click: true,
        probeType: 3
      })
      this.foodScroll.on('scroll', (pos) => {
        this.scrollY = Math.abs(Math.round(pos.y))
      })
    },
    _caculateHeight () {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook')
      let height = 0
      this.listHeight.push(height)
      for (var i = 0; i < foodList.length; i++) {
        let item = foodList[i]
        height += item.clientHeight
        this.listHeight.push(height)
      }
    }
  },
  components: {
    ShopCart,
    Cartcontrol,
    Food
  }
}
</script>
<style lang="stylus" rel="stylesheet/stylus">
  @import '~common/stylus/mixin'
    .goods
      display flex
      overflow hidden
      position absolute
      top 174px
      bottom 46px
      width 100%
      .menu-wrapper
        flex 0 0 80px
        width 80px
        background #f3f5f7
        .menu-item
          display table
          width 56px
          height 54px
          line-height 14px
          padding 0 12px
          &.current
            position relative
            margin-top -1px
            z-index 10
            background #fff
            font-weight bold
            .text
              border-none()
          .icon
            display inline-block
            vertical-align top
            width 12px
            height 12px
            margin-right 2px
            background-size 12px 12px
            background-repeat no-repeat
            &.decrease
              bg-image('decrease_3')
            &.discount
              bg-image('discount_3')
            &.guarantee
              bg-image('guarantee_3')
            &.invoice
              bg-image('invoice_3')
            &.special
              bg-image('special_3')
          .text
            display table-cell
            font-size 12px
            width 56px
            vertical-align middle
            border-1px(rgba(7, 17, 27, 0.1))
      .food-wrapper
        flex 1
        .title
          padding-left 14px
          height 26px
          line-height 26px
          border-left 2px solid #d9dde1
          font-size 12px
          color rgb(147, 153, 159)
          background #f3f5f7
        .food-item
          display flex
          margin 18px 18px 0 18px
          padding-bottom 18px
          border-1px(rgba(7, 17, 27, 0.1))
          &:last-child
            border-none()
          .icon
            flex 0 0 auto
            margin-right 10px
          .content
            flex 1
            .name
              margin 2px 0 8px 0
              height 14px
              line-height 14px
              font-size 14px
              color rgb(7, 17, 27)
            .desc, .extra
              line-height 10px
              font-size 10px
              color rgb(147, 153, 159)
            .desc
              margin-bottom 8px
              line-height 12px
            .extra
              .count
                margin-right 12px
            .price
              font-weight 700
              line-height 24px
              .now
                color rgb(240, 20, 20)
                margin-right 8px
                font-size 14px
              .old
                font-size 10px
                color rgb(147, 153, 159)
                text-decoration line-through
            .cartcontrol-wrapper
              position absolute
              right 0
              bottom 12px
</style>
